Lead service water pipe line removal apparatus and method

ABSTRACT

An apparatus and a method of extracting buried lead water supply pipe with minimal excavation and which allows removal and containment of the lead pipe. The extraction apparatus includes a frame having an upwardly extending mast, a guide pulley mounted on the frame, and a pulling apparatus. A take-up spool is mounted on the mast between the guide pulley and pulling apparatus and positioned to allow a pipe pulling cable to be wrapped therearound into a non-linear path between the guide pulley and the pulling apparatus. Extracted pipe is pulled into the non-linear path until the pipe is fully extracted from the ground. Multiple spiral loops around the take-up spool by the pulling cable may be necessary to fully contain the extracted pipe. Following extraction, the pipe may be unspooled from the take-up spool, the pulling cable removed for re-use, and the pipe may then be sent for disposal.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation in Part application of U.S.application Ser. No. 16/121,073 filed on Sep. 4, 2018, which is acontinuation of U.S. application Ser. No. 15/675,346, filed Aug. 11,2017.

BACKGROUND OF THE INVENTION

The present invention generally relates to the field of pipelinereplacement and, more particularly, to an apparatus and method forreplacing buried drinking water supply lines made of lead piping whichminimizes ground disruption and potential dispersion of the lead duringpipe removal.

It is estimated that there are over 6 million installations of leadpipes carrying drinking water from water supply mains to residences inthe United States. Due to the harmful effects of lead ingestion byhumans and other animals, replacement of this piping is becomingincreasingly imperative. In urban areas where space is tight and buriedinfrastructure is very dense, excavating buried pipelines forreplacement is particularly expensive and not always practical orfeasible.

Branch water service supply lines are generally less than 2 inches indiameter, with the majority being 1-inch or less. It is common to removethese pipes by accessing and freeing the ends of the pipe, attaching apulling apparatus to one end, and then pulling the pipe through theground in which it is buried. Sawing, grinding, and/or fracturing thepipe is not permissible as such operations have the potential todisperse lead particles into the environment. In some instances,replacement pipe will be secured to the end opposite of that beingpulled so that the replacement pipe is pulled into position as the oldpipe is being removed. Should the pipe being removed break during thepulling process, excavation of the pipe is required which eliminates anyadvantage of the pull-through replacement method. The risk of breakagewhen pulling from the leading end or wadding when pulling from thetrailing end is greater with lead pipes which are quite malleable andhave relatively low tensile strength.

An alternative method involves feeding a cable through the pipe to beremoved, securing the cable to the pipe, and then pulling the cable andpipe through the ground. While this approach overcomes limitations inthe strength of lead pipe, it does not allow for the lead pipe to beeasily separated from the cable during the pulling operation. The resultis generally that the pulling cable becomes sacrificial, increasing thecosts associated with the replacement operation. One such method isdisclosed in U.S. Pat. No. 8,277,147 issued to Cilliers which disclosessuch a method in which the cable is affixed within the pipe byintroduction of a settable fluid which secures the cable to the entirewetted length of the pipe interior.

It would be advantageous to provide a method of replacing buried leadwater supply pipe that overcomes these limitations.

SUMMARY OF THE INVENTION

The present invention includes an apparatus and a method of replacingburied lead water supply pipe with minimal excavation and which allowsremovable and containment of the lead pipe. The apparatus includes aleading collet and a lagging collet which are secured to opposite freeends of the lead pipe to be removed. A cable is directed through thepipe to be removed and connected to each of the collets. The cablelength should closely match the length of the pipe in which it isdirected. The pulling cable preferably extends from leading collet andis connected to a winch or similar pulling apparatus. A connector may beprovided on the leading collet to permit attachment of a second cable,such as the cable provided on a winch. The cable between the lead colletand the winch may be directed along a path which permits easy access tothe removed lead pipe following extraction from the ground. New pipelinemay be connected to the lagging collet so that the replacement pipelineis pulled into the void left by the replaced pipe as it is extracted.

A pipeline removal apparatus is provided to connect a winch apparatus tothe pipeline pulling cable in a manner that enables the entire length ofpipe to be removed from the ground and subsequently removed from thewinch apparatus without the need to cut the pipe, eliminating thepotential for creating airborne lead particles by having to cut pipefrom the removal apparatus as it is removed. To accomplish thisobjective, a frame with a reaction foot and winch means for pulling anextraction cable is positioned in the excavated access adjacent to thepipeline. The pulling cable is directed from a guide pulley adjacent tothe reaction foot, to a pipeline storage means disposed on the frame,and then to a winch which provides the pulling force to the cable. Thelength of the cable path through the pipeline storage means is at leastapproximately equal to the length of the pipeline to be removed to avoidentrainment of the extracted pipe in the winch apparatus.

In one embodiment, the pipeline storage means comprises a mast thatextends, typically vertically. The mast height above the reaction footand winch may be adjustable. The pulling cable is directed from a guidepulley adjacent to the reaction foot, around a second guide pulleypositioned at the distal end of the mast before connecting to the winch.As the pipeline is extracted from the ground it is pulled along theextended mast length without puling entrained in the winch. Once thepipeline is extracted from the ground, the pulling cable may be removedfrom the pipeline and the pipeline material disposed of. Cutting of thelead pipeline material is not required thus minimizing the generationand spread of lead contamination.

An alternative embodiment minimizes overhead clearance required foroperation. In lieu of an adjustable height mast, the alternativeembodiment includes a take-up spool connected to the mast and positionedbetween the lower guide pulley and the pulling apparatus. The take-upspool is preferably rotatably mounted to the mast and positioned so thatthe cable path between the guide pulley and the pulling apparatus isnon-linear, that is the pulling cable may be wrapped around the take-upspool. Further, multiple loops of the pulling cable may encircle thetake-up spool so that the pipeline is coiled on the spool as it isextracted from the ground. Once the pipeline is completely removed fromthe ground it may be unwound from the take-up spool, the pulling cableremoved, and the pipe disposed of. As before, the pipeline need not becut thus minimizing the generation and spread of lead contamination.

The method of replacing the pipe comprises the steps of:

Accessing the ends of the pipe that is to be replaced. This typicallyinvolves excavating the area adjacent to the user valve isolation boxand the area where the water supply line enters the building. It isoften possible to enlarge a wall penetration surrounding the watersupply line to permit the supply line to freely pass therethrough. Theremay also be a portion of supply pipe extending between the user valveisolation box (typically located at the edge of the right of waysurrounding the water main) and the water main. This portion may also beremoved using the method but requires excavation of the water main atthe supply line tap location.

Providing a pulling apparatus at the leading end of the pipe to beremoved. Pulling is typically from the end adjacent to the valveisolation box which provides greater access than locations immediatelyadjacent to or even within the building supplied by the water supplyline.

Configuring the pulling apparatus so that a cable connecting a winch tothe pipeline is directed along a path that exceeds the length of thepipe to be removed. To this end multiple loops of the cable may bewrapped around the take-up spool so that the length of the pulling cableencircling the take-up spool generally equal to or greater than thelength of the pipeline to be removed. The pulling apparatus is thenpositioned adjacent to the leading end of the pipe to be removed.

Directing a cable through the pipe to be removed. The cable may beintegral to cable provided on the pulling apparatus or a separate cablewith provisions for connecting to the pulling apparatus.

Attaching a leading collet and a lagging collet to respective ends ofthe pipe to be removed. The collets are configured to fixedly grasp boththe cable and the pipe to be removed.

Applying a pulling tension to the cable in the leading direction. Thetension is applied to the pipe to be removed at both the leading andlagging collets which prevents the entire pulling tension from beingapplied to the relatively weaker lead pipe. Continuing to pull thepipeline until it is extracted from the ground and positioned on thepulling apparatus but not enrolled in the winch.

Releasing the collets and extracting the cable from within the pipe thatwas removed. The lead pipe can then be disposed while the pullingapparatus, cable, and collets may be reused.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages of this invention will be apparent upon consideration ofthe following detailed disclosure of the invention, especially whentaken in conjunction with the accompanying drawings wherein:

FIG. 1 presents a side view of a typical pipeline replacementarrangement utilizing the method of the present invention;

FIG. 2 illustrates one embodiment of a cable connection collet of thepresent invention shown in a lagging or trailing position;

FIG. 3 is a cross-section illustration of the cable connection collet ofFIG. 2 shown in a leading position;

FIG. 4 is a section view of the of the cable connection collet of FIG. 2taken along cut line 4-4;

FIG. 5 shows a second view of FIG. 1 wherein the pipeline is partiallydisplaced during removal;

FIG. 6 provides side view of a typical water service supply pipeline ofthe type on which the present invention is useful;

FIG. 7 illustrates an alternate means for managing cable and extractedpipe take-up during a removal operation;

FIGS. 8 through 12 illustrate an alternate embodiment of a pipelineextraction apparatus embodying aspects of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Many of the fastening, connection, processes and other means andcomponents utilized in this invention are widely known and used in thefield of the invention described, and their exact nature or type is notnecessary for an understanding and use of the invention by a personskilled in the art, and they will not therefore be discussed insignificant detail. Also, any reference herein to the terms “up” or“down,” or “over” or “under,” or “above” or “below” are used as a matterof mere convenience and are determined from the perspective of theground surface. Furthermore, the various components shown or describedherein for any specific application of this invention can be varied oraltered as anticipated by this invention and the practice of a specificapplication of any element may already be widely known or used in theart by persons skilled in the art and each will likewise not thereforebe discussed in significant detail. When referring to the figures, likeparts are numbered the same in all figures.

Referring to FIG. 6, there is shown a diagrammatic elevation view of atypical arrangement of a buried water service supply line for abuilding, typically a residence. A water main 19 is typically buriedunder a street or other right-of-way to provide water to buildingssituated therealong. Taps 14 into the water main 19 allow connection ofservice supply lines comprising an extension line 15 and a servicesupply line 10. A service isolation valve 11 is typically providedproximate to the edge of the right-of-way. The service supply line 10extends through the ground 5 and typically penetrates a building 7,generally a below-grade wall and features an isolation valve 12, meter13, or other flow managing devices before being distributed to thebuilding interior.

For service supply lines comprising lead pipe material, replacement maybe accomplished with the instant invention. Referring to FIGS. 1 and 6,the service supply line is accessed, preferably by excavating a pipelineextraction access pit 18 around the service isolation valve 11. Onceexcavated, the valve is removed by shearing the pipe immediatelyupstream and downstream. An extraction apparatus 30 is positioned in theaccess pit 18 and the service supply line is disconnected at thebuilding end, typically by shearing the pipe and removing anypenetration sealant where the supply line 10 enters the building 7leaving both ends of the service supply line 10 open.

A first cable 32 is directed through the service supply line 10, thecable having strength tensile strength for removing the pipe and havinga diameter small enough to fit within the interior diameter of theservice supply line 10. Connecting collets 50 are positioned at each endof the service supply line, one being the leading collet 50 a and theother being the lagging collet 50b, determined by the direction in whichthe supply line 10 is to be pulled. The connecting collets areconfigured to simultaneously grip the supply line 10 and the first cable32 to create an integral structure having sufficient tensile strength towithstand the pulling forces.

An exemplar connecting collet is illustrated in FIGS. 2 and 3,comprising a clamshell or two-part generally cylindrical structurehaving first and second portions 51 a, 51 b that may be clampedsimultaneously around the cable 32 and supply line 10. A first bore 52is sized to surround the outside diameter of the service supply line 10.A second bore 54 is sized to surround the outside diameter of the firstcable 32. The first and second bores 52, 54 abut at a transition 56which is positioned to provide sufficient clamping area for the pipeline and the cable to preclude movement. The interior surface of thefirst and second bores 52, 52 is preferably provided with a grippingsurface 55 having a high coefficient of friction with the outer surfacesof the pipe line 10 and first cable 32 so that, when clamped, thecollets 50 resist movement in relation to the pipe line or cable. Asillustrated, the first and second portions 51 a, 51 b meet at joiningsurfaces 58 a, 58 b and are clamped together by tensioning fasteners 59.A small space is preferably provided between the joining surfaces toassure that sufficient clamping force is applied prior to contactbetween the surfaces. A connector 60 is provided to permit the leadingcollet 50 a to be connected to a second cable 33 which provides theextraction force for the pipeline 10. A similar connector 60 provided onthe lagging collet 50 b enables connection of a pull-through line oreven the replacement pipeline itself, the latter having the advantage ofremoving and replacing the water supply service line in a single pullingoperation.

The collet configuration as illustrated allows for a single colletconfiguration to be used in the leading or lagging location simply byreversing the orientation of the collet. Alternatively, the colletconfiguration may be specific to the leading or lagging position. Theconfiguration further includes tapered portions to ease passage of thelagging collet through the ground.

Other configurations of the collets 50 are envisioned that utilizevarious connections means to pipeline and/or cable. For example, barrelfixtures may be affixed to the cable portions by crimping or equivalentconnection, the fixtures having a finite axial length with a diameterexceeding the cable diameter. The fixture outer diameter is sized topermit passage through the inside diameter of the pipe while thetransition between cable and fixture provides a stepped shoulder forinterface with a matching profile on the inside diameter of the colletnormally configured to clamp the cable. The interface limits relativeaxial movement, whether uni- or bi-directionally, between the cable andcollet as would clamping the collet to the cable. Such configurationsenabling a fixed connection between pipeline and cable at leading andlagging locations are contemplated within the scope of the invention.

Now referring to FIGS. 1-5, the cable may be provided with one or moreconnectors 60 outboard of the pipeline 10 to permit connection of thepipeline 10/first cable 32 assembly to other assemblies. The leadingcollet 50 a is necessarily connected by the second cable 33 to a pullingapparatus 40 such as a winch which provides the tensioning force forpipeline removal. The second cable 33 is directed through a pipelineextraction apparatus 30 having a mast 34 and a plurality of pulleys 36a, 36 b, 36 c or the like to guide the first and second cables 32, 33along with the pipeline 10 surrounding the first cable 32. The pulleysinclude at least a first guide pulley 36 a positioned adjacent to thelocation at which the buried pipeline is exposed in the access pit and asecond guide pulley 36 b positioned at the distal end of the mast 34.Additional pulleys 36 c may be provided to guide the cables.

The mast extends generally orthogonally away from the axis of the pipeline 10, preferably upwardly out of the excavated access pit, and is ofsufficient height as to provide a take-up length that enables the lengthof the pipe line 10 to be removed to be fully supported on the mastwithout the pipe line 10 being engaged in the pulling apparatus 40(e.g., winch). This generally requires that the mast 34 be at leastapproximately half the height as the length of pipeline 10 beingremoved. In this configuration, the extracted pipe is deflected aroundthe first and second guide pulleys. It may be preferable for the mastlength to be at least that of the pipe to be removed so that theextracted pipe is only deflected around the only the first guide pulley36 a adjacent to the buried pipeline end which eases removal of thefirst cable 32 therefrom once the pipe is fully extracted from theground.

Removal of buried pipeline by pulling methods is best accomplished in asingle, continuous pull; interruptions of the pulling increase thechances of breaking the pipe line and increase wear and tear on thecables and cable tensioning apparatus.

The mast 34 may be provided with vertical adjustment means 39 to enablethe height of the mast (take-up length) to be altered to suit thespecific pipeline removal configuration of different removal locations.The vertical adjustment means may comprise mechanical connections 392which allow extension sections 34 b to be added between the base portion34 a and the distal portion 34 c to achieve the required take-up length.Extension sections 34 b may be provided in various lengths to enable asingle additional section 34 b to be used, or extension sections 34 bhaving a uniform length may be provided and the proper number ofextension sections 34 b incorporated to yield the desired mast height(take-up length). The mechanical connections 392 are preferably uniformin configuration and may include a flanged connection using uniformlyspaced bolted connections.

The mast 34 may also include articulated joints that enable the mast tobe conveniently compacted for transport when not in use. Sucharticulated joints may also be used to adjust the mast height to achievethe desired offset of the second guide pulley to achieve the requirecable take-up length.

Other mast configurations are also possible. FIG. 7 illustrates one suchalternative in which a pulling apparatus 40 is not available. The mast34 may comprise telescoping sections 341, 342 with a hydraulic cylinder345 or the like to selectively extend the telescoping sections. Thesecond cable 33 is connected at one end to a fixed structure (shown asthe base of the extraction apparatus in the figure). Tension isgenerated by extending the telescoping member. The cable connection mayinclude provisions to adjust the cable anchorage and a take-up apparatusprovided to increase the length of pipe than may be removed with theassembly. One disadvantage of this arrangement is a limited amount ofextension and thus pipeline movement that may be achieved in a singlestroke. The cable connection may include provisions to adjust the cableanchorage and a take-up apparatus provided to increase the length ofpipe than may be removed with the assembly, though this configuration isinherently limited by the amount of extracted lead pipe that may be heldon the apparatus and the need to remove extracted lead pipe therefrom.The advantage is a more compact footprint for the extraction apparatuswhich may work well when short service supply line lengths are involved.

The extraction apparatus 30 further comprises lateral and verticalreaction blocks 35, 37 to withstand the reaction forces of the secondcable 33, which may be on the order of 4,000 to 10,000 lbf.

Once the pipeline 10 is extracted from the ground 5 and preferablesupported on the extraction apparatus, the collets 50 and the interior(first) cable 32 are removed from the extracted pipeline 10. Thepipeline 10 may then be contained and scrapped while the cable andcollets are available for reuse. Once the first cable 32 is removed, thepipeline 10 may be cut by shearing into easily manageable length fordisposal or recycling. The requirement to cut lead pipe by shearinginstead of cutting or fracturing requires that any inserted material beremoved prior to shearing. Otherwise such materials must be scrappedalong with the extracted pipeline.

Removal of the extension line 15 between the main 19 and the serviceisolation valve 11 may be easily accomplished by realigning theextraction apparatus and directing the first cable 32 through theextension line 15. Most lead removal and replacement efforts involvedexcavation of the service main thereby facilitating assess to the distalend of the extension line adjacent to the tap 14.

In FIGS. 8 through 12, an alternative embodiment is illustrated forlocations having limited overhead clearance preventing the mast 34 frombeing properly positioned. The extraction apparatus 30 comprises a mast34 upwardly extending from a supporting base 50 for the apparatus. Inthis embodiment the extraction apparatus is preferably operablyconnected to a prime mover, such as a skid-steer-loader, eliminating theneed for a vertical reaction block. The base 50 allows the apparatus 30to support itself, either in a pipeline extraction pit or on a generallylevel surface when it is not in use. Lateral reaction blocks 35 areattached to the base 50. A first guide pulley 35 a is rotatablyconnected to the mast 34 to guide the cables 32, 33 from the generallyhorizontal orientation of the pipeline 10 to an upward orientation foralignment with the extraction apparatus.

The pulling apparatus (winch) 40 may be attached to the mast 34 at anupper end 42 distally opposed from the first guide pulley 35 a. Theseparation between the pulling apparatus 40 and the base 50 is minimizedto limit extension of the mast above grade level. In the embodimentillustrated, the pulling apparatus 40 is powered by a hydraulic powertake-off from the mobile skid-steer loader to which the extractionapparatus 30 is connected.

A take-up spool 72 is mounted on the mast 34 intermediately between thepulling apparatus 40 and the first guide pulley 35 a, preferablyrotatably mounted. The take-up spool forces the pulling cable to followa non-linear path between the first guide pulley 35 a and the pullingapparatus 40, best illustrated in FIGS. 11 and 12 as cable paths “A” and“B”, in order to increase the length of pipe line 10 that may bepositioned, once extracted from the ground, on the extraction apparatus30. In use, the second cable 33 may encircle the periphery 722 of thetake-up spool 72 multiple times before being directed to the pullingapparatus 40 (winch), the number of loops dictated by the length ofpipeline to be extracted. Ideally, the second cable is wrapped aroundthe take-up spool a number of turns so that the length of the secondcable encircling the take-up spool is generally equal to the length ofpipeline to be removed. As the first and second cables 32, 33 are pulledto withdraw the pipeline 10 from the ground, the first cable 32 andextracted pipe line 10 are wound onto the take-up spool as the pullingapparatus pulls the second cable is unwound from the take-up spool andonto the winch thereby pulling the pipe line from the ground. With thelength of the pipeline 10 known, the number of wraps of the cablesaround the periphery 722 necessary to contain the length of pipeline 10being extracted may be determined. The cables must be directed aroundthe take-up spool before attaching to the pipeline and beginning theextraction process. For this reason, the take-up spool 72 circumferenceand width are sized sufficiently large to provide ample space forextracted pipeline without requiring the pulling cables to overlap onthe take-up spool circumference (e.g., the cable spirally wraps thespool in a single layer). Once the pipeline is fully extracted from theground, the first cable 32 and the pipeline in which it is located maybe unspooled from the take-up spool and the first cable 32 extractedfrom the pipeline 10. In this manner, the lead pipeline may be scrappedwhile the cable may be reused. In use, an estimate of the length ofpipeline to be extracted allows an estimated number of wraps around theperiphery 722 to be determined so that the pipeline, once removed, willbe substantially contained on the take-up spool and not pulled into thepulling apparatus spool.

It is preferable for the height of the extraction apparatus to be lessthan eight feet so that it may be easily maneuvered and positioned in apipe extraction access pit with minimal risk of interference withoverhead utilities (e.g., electric or communication wires) proximate tothe access pit. The extraction apparatus 30 is preferably supportedadjacent the uppermost end of the mast 34. Vertical adjustment means 39may be provided in the mast 34 to accommodate a range of excavateddepths of pipeline removal trenches in which the pipeline extractionapparatus 30 may be used. The vertical adjustment means 39 enables thenormal height of the extraction apparatus to be minimized whileproviding flexibility of use in locations having significant frost linedepths or where pipes are buried deeply. Lateral adjustment means 54 mayalso be provided to position the reaction blocks 35 in adjacent contactwith a reaction surface in the extraction pit. In the illustratedembodiment, both adjustments means are accomplished by telescopingmembers 52, 62 manually secured in position by a pin 53, 63 engaging oneof a plurality of adjusting holes 55, 65. Alternative adjusting meansinclude mechanical jacks and hydraulic actuators positioned to extend orretract respective telescoping members.

Guides may be provided adjacent to the winch 40 or guide pulley 35 a toassure that the cables and/or pipeline 10 are not overlain on thetake-up spool 72. Such guides may be connected to the base 50 or mast34. Alternatively, winch 40 may be reoriented so that the cable pullfavors one end of the take-up spool 72.

It will be understood that changes in the details, materials, steps andarrangements of parts which have been described and illustrated toexplain the nature of the invention will occur to and may be made bythose skilled in the art upon a reading of this disclosure within theprinciples and scope of the invention. The foregoing descriptionillustrates the preferred embodiment of the invention; however,concepts, as based upon the description, may be employed in otherembodiments without departing from the scope of the invention.

Having thus described the invention, what is claimed is:
 1. A pipeextraction apparatus for pulling a length of buried pipe from the groundcomprising: a base frame having an upwardly extending mast; a firstguide pulley connected to the base frame; a cable pulling apparatushaving a pull cable moveable in at least a retracting direction, thepull cable being connectable to the buried pipe; and a cable take-upspool rotatably connected to the mast, the pull cable encircling androtating the cable take-up spool as the cable pulling apparatus movesthe pull cable in the retracting direction to extract the buried pipefrom the ground, the buried pipe pulled from the ground wrapping aroundthe take-up spool as the pull cable is retracted by the cable pullingapparatus.
 2. The pipe extraction apparatus of claim 1, wherein the pullcable encircles the cable take-up spool at least once.
 3. The pipeextraction apparatus of claim 2, wherein the pull cable encircles thecable take-up spool to wrap a length of the pull cable therearound, thelength being approximately the same as the length of the buried pipe. 4.A pipe extraction apparatus for pulling a length of buried pipe from theground comprising: a pull cable moveable by a cable pulling apparatus inat least a retracting direction, the pull cable being attachable to anend of the buried pipe; and a rotatable take-up spool disposed betweenthe cable pulling apparatus and the attachment to the buried pipe, thepull cable encircling the take-up spool and rotating the cable take-upspool as the cable pulling apparatus moves the pull cable in theretracting direction to extract the buried pipe from the ground, theburied pipe pulled from the ground wrapping around the take-up spool asthe pull cable is retracted by the cable pulling apparatus.
 5. The pipeextraction apparatus of claim 4, wherein the pull cable encircles thecable take-up spool one or more times to wrap a length of the pull cabletherearound, the length of the pull cable being approximately the sameas the length of the buried pipe to be extracted.